Jeffrey D. Sachs writes:

The solution to human-induced climate change is finally in clear view. Thanks to rapid advances in zero-carbon energy technologies, and in sustainable food systems, the world can realistically end greenhouse-gas emissions by mid-century at little or no incremental cost, and with decisive benefits for safety and health. The main obstacle is inertia: politicians continue to favor the fossil-fuel industry and traditional agriculture mainly because they don’t know better or are on the take.

Most global warming, and a huge burden of air pollution, results from burning fossil fuels: coal, oil, and gas. The other main source of environmental destruction is agriculture, including deforestation, excessive fertilizer use, and methane emissions from livestock. The energy system should shift from heavily polluting fossil fuels to clean, zero-carbon energy sources such as wind and solar power, and the food system should shift from feed grains and livestock to healthier and more nutritious products. This combined energy-and-food transformation would cause net greenhouse-gas emissions to fall to zero by mid-century and then become net negative, as atmospheric carbon dioxide is absorbed by forests and soils.

Reaching net-zero emissions by mid-century, followed by negative emissions, would likely secure the goal of limiting global warming to 1.5º Celsius relative to Earth’s pre-industrial temperature. Alarmingly, warming has already reached 1.1ºC, and the global temperature is rising around 0.2ºC each decade. That’s why the world must reach net-zero emissions by 2050 at the latest. The shift toward clean energy would prevent hundreds of thousands of deaths each year from air pollution, and the shift to healthy, environmentally sustainable diets could prevent around ten million deaths per year. [Continue reading…]